US researchers perfect gecko-style glue

Scientists at the University of California at Berkeley have developed an adhesive that mirrors the attach and easy release characteristics of a gecko's feet.

The material could prove useful in a range of products, from climbing equipment to medical devices, according to its developers.

Unlike traditional glue-based adhesives, the new material is made from millions of tiny plastic fibres that establish grip. Just two square centimetres of the material can support weights of 400 grams.

The researchers explained that the new adhesive brushes along a surface to develop traction and sticks as it slides on a surface, and releases as it lifts, in the same way that allows a gecko to achieve its speedy vertical escapes.

While ideal for hanging posters, the characteristic is even more important for any application that requires movement, such as climbing.

"The gecko has a very sophisticated hierarchical structure of compliant toes, microfibres, nano-fibres and nano-attachment plates that allows the foot to attach and release with very little effort," said co-author and Berkeley professor Ron Fearing.

"The gecko makes it look simple, but the animal needs to control the directions it is moving its toes. Correct movement equates to little effort."

The material also gets stronger with use and tightens its hold as it is rubbed repeatedly against a glass plate.

The extra strength is caused by the fibres bending over to make more contact, yet returning to their original shape once released.

A video showing the tape under testing in the laboratory is available here.